Video signal recording/reproduction device having dropout compensation function

ABSTRACT

In a VTR for a TCI signal, time-base correction and TCI decode processing are applied to the reproduced TCI signal of each channel and also to the corresponding dropout signals. According to the resulting dropout signal for luminance signal and the dropout signal for chrominance signal, the dropout section of a luminance signal and the dropout section of a chrominance signal are respectively compensated for. As a result, a luminance signal may have the data of the dropout section compensated for with data of a highly correlated luminance signal of 1H before and 1H after the horizontal period where dropout occurs. The dropout compensation circuits can be simplified since the luminance and chrominance signals are processed by separate circuits.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to video signalrecording/reproduction devices, and more particularly, to a video signalrecording/reproduction device such as a video tape recorder (VTR) for ahigh definition television comprising dropout compensation function forcompensating for dropouts of reproduced video signals.

2. Description of the Background Art

In recent years, the demand for high quality television image is rapidlyincreasing, whereby the so-called high definition television systemhaving the number of horizontal scanning lines increased significantlyin comparison with a conventional television system is being developedto meet these requirements. The development of associated equipments isalso in advance to implement the high definition television system. Onesuch equipment is a VTR employing a TCI (Time Compressed Integration)signal as a recording signal format. This TCI signal is obtained bytime-base processing the base band signals of a chrominance signal and aluminance signal to time-divisionally multiplex these signals within thesame horizontal period. Such VTRs are implemented to FM record the TCIsignal obtained by encoding the chrominance signal and the luminancesignal in the above described manner on a magnetic tape as a recordingmedium, at the time of recording, and to decode the TCI signalreproduced from the magnetic tape to restore the chrominance signal andthe luminance signal at the time of reproduction.

Missing reproduced video signals in some sections, i.e. dropout ofreproduced video signals, due to dust and scratch on the recordingmedium such as a magnetic tape, often occurs in a video signalrecording/reproduction device such as a VTR. Video signalrecording/reproduction devices are generally provided with a devicecompensating for dropout. One such conventional dropout compensationdevice is disclosed in Japanese Patent Laying-Open No. 63-232778, forexample.

FIG. 1 is a block diagram schematically showing a general dropoutcompensation device adopted in a video signal recording/reproductiondevice such as a VTR. Referring to FIG. 1, a video signal reproducedfrom a recording medium such as a magnetic tape (not shown) is convertedinto a digital data by an A/D converter not shown and provided to a 1Hline memory 1 and to one input of an adder 2. A dropout pulse DO, isapplied to a 1H memory 3 and an inverter 4 from a dropout detector notshown, which indicates whether there is dropout in the reproduced videosignal. This dropout pulse DO, is at a high level when there is nodropout in the reproduced video signal, and at a L level when there isdropout. Dropout pulse DO, is inverted by inverter 4 to be applied to 1Hline memory 1 as a write enable signal WE'.

When there is no dropout in the reproduced video signal, signal WE' isat a L level, whereby the reproduced video signal is written into 1Hline memory 1. When there is dropout in the reproduced video signal,signal WE' is at the H level, whereby the writing of the reproducedvideo signal into 1H line memory 1 is inhibited during that period.Regarding the reproduced signal written into 1H line memory 1, the dataof the period where dropout occurs is replaced by data of acorresponding period of a reproduced video signal of 1H before held in1H line memory 1.

The reproduced video signal is delayed by 1H by 1 line memory 1 andapplied to one contact 5a of a switch circuit 5 and to the other inputof adder 2. Meanwhile, dropout pulse DO, is delayed by 1H by 1H memory3, and applied to a control input of switch circuit 5 as a selectingsignal SEL. During the period where there is no dropout in thereproduced video signal, i.e. the period where signal SEL is at the Hlevel, switch circuit 5 is connected to contact 5a, whereby thereproduced video signal delayed by 1H is directly output from 1H linememory 1 through switch circuit 5. During the period where there is dropout in the reproduced video signal, i.e. the period where signal SEL isat the L level, switch circuit 5 is connected to contact 5b. As aresult, the reproduced video signal supplied from 1H line memory 1 andthe reproduced video signal currently being written into 1H line memory1 are added to each other by adder 2, and the amplitude of the resultantsignal is attenuated to 1/2 by an attenuator 6. This means that theaverage value of the signals in the corresponding sections in thereproduced signals of 1H before and 1H after the horizontal period wheredropout occurs is output from switch circuit 5.

FIG. 2 is a waveform chart explaining the operation of the dropoutcompensation device of FIG. 1. Referring to FIG. 2, (a) represents thereproduced video signal applied to 1H line memory 1 and to one input ofadder 2. The section marked "S" indicates the dropout. A referencenumeral "7" indicates the horizontal synchronizing signal.

The reproduced video signal is delayed by 1H, as shown in FIG. 2 (b), bybeing stored in 1H line memory 1. The writing of the reproduced videosignal into 1H line memory 1 is inhibited during period S where dropoutoccurs. The data of that section is replaced with data t of thecorresponding section T in the reproduced video signal of 1H before.

Then, data t of period S in the reproduced video signal delayed by 1H,and data u of the corresponding section U of the currently reproducedvideo signal, i.e. the reproduced video signal of 1H after thehorizontal period where dropout occurs, are added to each other andaveraged according to selecting signal SEL shown in FIG. 2 (c). Thedropout of period S is compensated for by the average value v obtainedby the above mentioned adding and averaging, as shown in FIG. 2 (d).

A VTR of high definition television system generally carries outrecording and reproduction of the TCI signal for each channel bydividing the TCI signal into 2 channels. When dropout is compensated foreach channel in such VTRs according to the process shown in FIGS. 1 and2, an average value of data of 2H before and 2H after the horizontalperiod where dropout occurs is used for compensation. This means thatthe correlation between the reproduced video signals is reduced todeteriorate the quality of the picture, in comparison with the casewhere compensation is carried out using the average value of data of 1Hbefore and 1H after the horizontal period where dropout occurs.

A possible consideration to solve this problem is to compensate fordropout using data of 1H before and 1H after the horizontal period wheredropout occurs by substituting data between the two channels of thereproduced TCI signal. However, guard bandless recording of two channelsis susceptible to dropout generation in both channels at the same time.Dropout cannot be compensated for sufficiently unless relatively largecapacity memories such as frame memories or field memories are used.

There was also a problem that processing circuitry for dropoutcompensation becomes complicated because the TCI signal with thechrominance signals line sequential processed has different distancesupon the time base of data used for dropout compensation regarding thechrominance data section and the luminance data section.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a video signalrecording/reproduction device for a TCI signal suppressing thedeterioration of picture quality associated with dropout compensation.

Another object of the present invention is to provide a video signalrecording/reproduction device for a TCI signal having simplified dropoutcompensation circuit structure.

Briefly stated, the present invention is a video signalrecording/reproduction device for recording/reproducing a TCI signal oftwo channels obtained by time-divisionally multiplexing a luminancesignal and a line sequential processed chrominance signal within onehorizontal period; including a TCI signal reproducing circuit, a dropoutdetecting circuit, a time-base correcting circuit, a decode circuit forTCI signal, a dropout compensation circuit for luminance signal, and adropout compensation circuit for chrominance signal. The TCI signalreproducing circuit reproduces the TCI signal of each channel from therecording medium. The dropout detecting circuit detects the section inthe reproduced TCI signal of each channel where dropout occurs togenerate a dropout signal indicating the dropout section. The time-basecorrecting circuit corrects the time-bases of the reproduced TCI signalof each channel and the corresponding dropout signals. The decodecircuit for TCI signal decodes the reproduced TCI signal having thetime-base corrected to restore a luminance signal and a chrominancesignal. The decode circuit also decodes the dropout signals having theirtime-bases corrected to generate a dropout signal for luminance signalindicating the dropout section of a luminance signal, and a dropoutsignal for chrominance signal indicating the dropout section of achrominance signal. The dropout compensation circuit for luminancesignal compensates for the dropout section of the luminance signalrestored by the decode circuit, according to the dropout signal forluminance signal. The dropout compensation circuit for chrominancesignal compensates for the dropout section of the chrominance signalrestored by the decode circuit, according to the dropout signal forchrominance signal.

The main advantage of the present invention lies in that the dropoutsections of a luminance signal and a chrominance signal restored bydecoding a TCI signal are respectively compensated according to adropout signal for luminance signal and a dropout signal for chrominancesignal generated by time-base correcting and TCI decoding the dropoutsignal as for a reproduced TCI signal, whereby the luminance signal canbe compensated for dropout with highly correlated luminance signal dataof 1H before and 1H after the horizontal period where dropout occurs, tosuppress deterioration in picture quality.

Another advantage of the present invention lies in that each structureof the dropout compensation circuit for luminance signal and the dropoutcompensation circuit for chrominance signal are simplified becausedropout compensation is respectively carried out after the reproducedTCI signal is decoded and divided into a luminance signal and achrominance signal.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a general dropout compensation circuitadopted in a conventional VTR.

FIG. 2, consisting of (a)-(d),is a waveform chart explaining theoperation of the dropout compensation circuit of FIG. 1.

FIG. 3 is a block diagram showing a reproduced signal processing systemof a VTR according to an embodiment of the present invention.

FIG. 4 is a block diagram showing the structure of the TBC of FIG. 3.

FIG. 5 is a block diagram showing the structure of the TCI decoder ofFIG. 3.

FIG. 6, consisting of (a)-(h), is a waveform chart specifically showingthe decode processing manner of the TCI decoder of FIG. 5.

FIG. 7, consisting of (a)-(f), is a timing chart schematically showingthe principle of the decode process of the TCI decoder of FIG. 5.

FIG. 8 is a block diagram showing the structure of a dropoutcompensation circuit for luminance signal of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 3 is a block diagram showing a reproduced signal processing systemof a VTR of an embodiment of the present invention. This VTR is for highdefinition televisions according to 2-channel divided TCI signalrecording systems. The reproduction of a FM-modulated TCI signalrecorded on a magnetic tape not shown will be explained hereinafter. Itis assumed that the chrominance signals are line sequential processed inbeing encoded into a TCI signal.

Referring to FIG. 3, RF signals of two channels reproduced from amagnetic tape by magnetic heads not shown, i.e., the reproduced RFsignals of channel A (chA) and channel B (chB) are FM demodulated by FMdemodulators 11 and 12 to result in analog reproduced TCI signals,respectively. The reproduced TCI signals of channel A and channel B arerespectively applied to TBCs (Time Base Corrector) 13 and 14 fortime-base correction.

The reproduced RF signals of channel A and channel B are also providedto dropout detectors 15 and 16, respectively. Each dropout detectordetects the section where dropout occurs according to the envelope ofthe applied reproduced RF signal to generate a dropout pulse as adropout signal indicating such a dropout section. Such a dropout pulseis a signal which is at a L level during the period of dropoutoccurrence, and at a H level otherwise. The dropout pulses of channel Aand channel B are applied to TBCs 13 and 14, respectively.

As will be explained in detail later, each of TBCs 13 and 14 convertsthe applied reproduced TCI signal of the corresponding channel into adigital data by an A/D converter contained therein according to a clocksignal synchronized with the reproduced TCI signal, to write the sameinto a contained memory having a storage capacity of several lines forexample. Then, digital data corresponding to the reproduced TCI signalis read out from that memory according to a stable reference clocksignal, whereby time-base correction of the reproduced TCI signal iscarried out.

TBCs 13 and 14 also carry out the time-base correction with respect tothe dropout pulses of the corresponding channel A and channel B,similarly to the above-mentioned reproduced TCI signal. Because A/Dconversion as in the case of the above-mentioned reproduced TCI signalis not necessary in the case of a dropout pulse, synchronization withthe reproduced TCI signal is performed by writing the dropout pulse intothe contained memory according to the clock signal synchronized with thereproduced TCI signal.

The digital TCI signals and dropout pulses having their time-basescorrected by TBCs 13 and 14 are provided to a TCI decoder 17. TCIdecoder 17 decodes the TCI signals of channel A and channel Balternately provided from TBCs 13 and 14 to restore a luminance signaland a chrominance signal.

Furthermore, TCI decoder 17 decodes the dropout pulses of channel A andchannel B to generate a dropout pulse for luminance signal indicatingthe dropout section of a luminance signal and a dropout pulse forchrominance signal indicating the dropout section of a chrominancesignal.

The luminance signal and the dropout pulse for luminance signal providedfrom TCI decoder 17 are applied to a dropout compensation circuit 18 forluminance signal, where dropout compensation is carried out for theluminance signal to provide a luminance signal Y.

Meanwhile, the chrominance signal and the dropout pulse for chrominancesignal provided from TCI decoder 17 are applied to a dropoutcompensation circuit 19 for chrominance signal, where dropoutcompensation for the chrominance signal is carried out. This chrominancesignal is applied to an interpolation circuit for chrominance 20, wherethe necessary interpolation process is carried out for the chrominancesignal. This chrominance signal is divided and output as chrominancesignals C1 and C2.

FIG. 4 is a block diagram showing in detail each structure of TBCs 13and 14. Each of TBCs 13 and 14 comprises a line memory 32 of 1 word8-bit structure for reproduced TCI signal capable of asynchronousreading and writing, and a line memory 34 of 1 word 1-bit structure fordropout pulses capable of asynchronous writing and reading.

Referring to FIG. 4, the reproduced TCI signal provided from thecorresponding FM demodulator 11 or 12 is applied to an A/D converter 31,a write clock generator 35, and a reproduction synchronization detector36. The write clock generator 35 generates a write clock signal W_(ck)according to the reproduced TCI signal, and applies the same to A/Dconverter 31, a latch circuit 33, and a write control circuit 37. Thereproduction synchronization detector 36 separates a horizontalsynchronizing signal from the reproduced TCI signal, and applies thesame to write control circuit 37.

A/D converter 31 is responsive to a write clock signal W_(CK) from writeclock generator 35 to convert the reproduced TCI signal into a digitalsignal. This digital signal is applied to line memory 32 for time-basecorrection. The digital TCI signal is written into line memory 32according to a control signal from write control circuit 37.

A read control circuit 38 generates a control signal according to areadout clock signal R_(CK), a TCI horizontal synchronizing signal and aframe pulse F_(P) from a reference signal generator not shown. Inresponse to this control signal, a digital data corresponding to thereproduced TCI signal is readout from line memory 32, whereby time-basecorrection is carried out for the reproduced TCI signal.

The dropout pulse provided from the corresponding dropout detectors 15or 16 is applied to latch circuit 33 to be latched according to writeclock signal W_(CK). This causes the dropout pulse to be synchronizedwith the reproduced TCI signal, and is written into line memory 34according to a control signal from write control circuit 37. The dropoutpulse is read out from line memory 34 according to a control signal fromread control circuit 38, whereby time-base correction of the dropoutpulse is carried out.

FIG. 5 is a block diagram showing in detail the structure of the TCIdecoder 17 of FIG. 3. FIG. 6 is a waveform chart specifically showingthe decode processing of the TCI decoder 17, whereas FIG. 7 is a timingchart schematically showing the principle of the decode process.

In FIGS. 6 and 7, the TCI signal is constituted by chrominance signalsC1 and C2, and luminance signal Y which are time-divisionallymultiplexed. The small size suffixes in the figures _(N), N+1 . . . arenumbers for each signal indicating the numerical order of each ofsignals Y, C1 and C2. A reference numeral "21" in FIG. 6 indicates ahorizontal synchronizing signal.

Referring to FIG. 5, TCI decoder 17 comprises a first line memory 41 forluminance signal corresponding to channel A, a second line memory 42 forluminance signal corresponding to channel B and a line memory 44 forchrominance signal. Each of memories 41, 42 and 44 are capable ofasynchronous writing and reading.

It is assumed that there are dropout sections at Cl_(N), Y_(N) andY_(N+4) in the reproduced TCI signal of channel A provided from TBC 13of FIG. 3, as shown in FIG. 6(a). Corresponding to these dropoutsections, dropout pulses I, II and III of channel A are provided fromTBC 13, as shown in FIG. 6 (b). It is also assumed that there aredropout sections at C2_(N+1) and Y_(N+3) in the reproduced TCI signal ofchannel B provided from TBC 14. Corresponding to these dropout sections,dropout pulses IV and V of channel B are provided from TBC 14, as shownin FIG. 6(d).

The above-mentioned TCI signal of channel A (FIG. 6 (a) and FIG. 7 (a))and the dropout pulse of channel A (FIG. 6 (b)) provided from TBC 13 arestored in the first line memory 41 for luminance signal in TCI decoder17. The above-mentioned TCI signal of channel B (FIG. 6 (c) and FIG. 7(b)) and the dropout pulse of channel B (FIG. 6 (d)) provided from TBC14 of FIG. 3 are stored second line memory 42 for luminance signal inTCI decoder 17.

According to the timing signal generated by timing generator 45 inresponse to TCI horizontal synchronizing signal, frame pulse F_(P) andclock signal R_(CK), luminance signals are read out alternately from thefirst and second line memories 41 and 42 for luminance signal, as shownin FIGS. 7 (c) and (d), and applied to a multiplexer 43 for luminancesignal. The luminance signals applied to multiplexer 43 for luminancesignal are mixed with each other as shown in FIGS. 6 (e) and 7 (e) to besupplied. According to the timing signal from timing generator 45, thedropout pulses of channels A and B are read out from the first andsecond line memories 41 and 42 for luminance signal, and mixed with eachother by multiplexer 43 for luminance signal. That is to say, dropoutpulses VI, VII and VIII for luminance signal corresponding to theabove-mentioned dropout sections II, V and III (FIGS. 6 (b) and (d)) inluminance signal Y_(N), Y_(N+3) and Y_(N+4) are provided frommultiplexer 43 for luminance signal, as shown in FIG. 6 (f).

According to the timing signal from timing generator 45, chrominancesignals C1 and C2 are read out from line memory 44 for chrominancesignal, as shown in FIGS. 6 (g) and 7 (f), to be supplied. Alsoaccording to the timing signal from timing generator 45, dropout pulsescorresponding to chrominance signals C1 and C2 are read out from linememory 44 for chrominance signal. That is to say, dropout pulses IX andX for chrominance signal corresponding to the above-mentioned dropoutsections I and IV (FIGS. 6 (b) and (d)) in chrominance signals Cl_(N)and C2_(N+1) are provided from line memory 44 for chrominance signal, asshown in FIG. 6 (h). In the above mentioned TCI decoder 17, data of 9bits constituted by a video data of 8 bits and a dropout pulse of 1 bitis processed. Each of line memories 41, 42 and 44 implementing TCIdecoder 17 has a 1 word 9-bit structure.

FIG. 8 is a block diagram showing in detail the structure of the dropoutcompensation circuit 18 for luminance signal of FIG. 3. Referring toFIG. 8, the luminance signal provided from TCI decoder 17 (FIGS. 6 (e)and 7 (e)) is applied to 1H line memory 22 and to one input of adder 23.The dropout pulse DO for luminance signal provided from TCI decoder 17is applied to a data selecting circuit 24. Dropout pulse DO is alsoprovided to an inverter 25 to be inverted and applied to 1H line memory22 as a write enable signal WE.

That is to say, during the period where dropout section does not existin the reproduced luminance signal, signal DO is at H level, wherebysignal WE attains the L level. Accordingly, the reproduced luminancesignal of that period is written into 1H line memory 22. During theperiod where dropout section exists in the reproduced luminance signal,signal DO is at L level, whereby signal WE attains the H level.Accordingly, the writing of the reproduced luminance signal into 1H linememory 22 is inhibited during that period. Regarding the reproducedluminance signal written into 1H line memory 22, data of a period wheredropout occurs is replaced with the data of a corresponding period inthe reproduced luminance signal of 1H before held in 1H line memory 22.If there is dropout also in the luminance signal of 1H before,replacement will be performed again with the data of a correspondingperiod in a reproduced luminance signal of a preceeding horizontalperiod.

As stated before, the reproduced luminance signal is delayed by 1H by 1Hline memory 22 and applied to one contact 26a of switch circuit 26 andto the other input of adder 23. Adder 23 adds the delayed luminancesignal provided from 1H line memory 22 to the reproduced luminancesignal currently provided, whereby the output amplitude thereof isdivided by 2 by a divider 27. This means that the average value of thetwo inputs of adder 23 is applied to contact 26b of switch circuit 26.The reproduced luminance signal currently provided from TCI decoder 17is applied to contact 26c of switch circuit 26.

The data selecting circuit 24 is responsive to the dropout pulse forluminance signal from TCI decoder 17 to generate selecting signals C andD. These selecting signals are provided to the control inputs of switchcircuit 26. According to these selecting signals, switch circuit 26 isconnected to any of contacts 26a-26c, whereby any of the output of 1Hline memory 22, the output of divider 27 and the currently reproducedluminance signal is supplied as luminance signal Y via switch circuit26.

The switching operation by switch circuit 26 of FIG. 8 will be explainedhereinafter.

Case 1

When there is no dropout in the luminance signal currently provided from1H line memory 22, switch circuit 26 is switched to the side of contact26a in response to selecting signals. As a result, a luminance signaldelayed by 1H is directly provided from 1H line memory 22 via switchcircuit 26.

Case 2

When there is dropout in the luminance signal currently provided from 1Hline memory 22, and no dropout in the luminance signals of 1H before and1H after thereof, switch circuit 26 is connected to the side of contact26b in response to selecting signals. As a result, the average value ofthe signals of the corresponding sections in the luminance signals ofhorizontal periods 1H before and 1H after the horizontal period wheredropout occurs is provided via switch circuit 26.

Case 3

When there are dropouts in the luminance signal currently provided from1H line memory 22 and in the luminance signal of 1H before, and nodropout in the luminance signal of 1H after, switch circuit 26 isswitched to the side of contact 26c in response to selecting signals. Asa result, the luminance signal of 1H after the horizontal period wheredropout occurs is provided via switch circuit 26.

Case 4

When there are dropouts in the luminance signal currently provided from1H line memory 22 and in the luminance signal of 1H after, and nodropout in the luminance signal of 1H before, switch circuit 26 isconnected to the side of contact 26a in response to selecting signals.As a result, the luminance signal from 1H line memory 22 is directlyprovided via switch circuit 26.

Case 5

When there are dropouts in the luminance signal currently provided from1H line memory 22 and in the luminance signals of 1H before and also 1Hafter, switch circuit 26 is connected to the side of contact 26a inresponse to selecting signals. As a result, a luminance signal whereinthe signal of the dropout period is replaced by a signal of a horizontalperiod of several Hs before where there are no dropouts is provided viaswitch circuit 26.

Thus, in accordance with an embodiment of the present invention,deterioration of picture quality at the time of dropout compensation canbe prevented when there is dropout in the luminance signal currentlyprovided from the 1H line memory, by detecting whether there aredropouts or not in the luminance signals of 1H before and 1H after, andsubstituting luminance signal data having the highest correlation withthe current reproduced signal for luminance signal data of the periodwhere dropout occurs.

The structure of the dropout compensation circuit 19 for chrominancesignal that compensates for dropouts of line sequential processedchrominance signals C1 and C2 is substantially similar to that of thedropout compensation circuit 18 of FIG. 8. The dropout compensationcircuit 19 is implemented with a 2H line memory instead of the 1H linememory 22 of FIG. 8, whereby each dropout section of each of signals C1and C2 is replaced by data of each signal of 2H before and 2H after, oran average value of signals of corresponding sections in the chrominancesignals in the horizontal periods 2H before and 2H after the horizontalperiod where dropout occurs. Only one system of dropout compensationcircuit 19 for chrominance signal is required because chrominancesignals are line sequential processed, as stated before.

Although a VTR for high definition television is taken as an example inthe above embodiment, the present invention can be applied to videosignal recording/reproduction devices using magnetic disc, optical discand the like as the recording media of video signals.

Although the present invention has been described and illustrated indetail, it is clearly understood that the same is by way of illustrationand example only and is not to be taken by way of limitation, the spiritand scope of the present invention being limited only by the terms ofthe appended claims.

What is claimed is:
 1. A video signal recording/reproduction device for recording and reproducing a 2-channel TCI signal obtained by time-divisionally multiplexing a luminance signal and a line sequential processed chrominance signal within one horizontal period, comprising:means for reproducing a TCI signal for each channel from a recording medium, dropout detecting means for detecting the section where dropout occurs in the reproduced TCI signal of each channel to generate a dropout detection signal indicating the corresponding dropout section of each channel, time-base correcting means for time-base correcting the reproduced TCI signal of each channel and the corresponding dropout detection signal of each channel, decode means for decoding the reproduced, time-base corrected TCI signal of each channel to restore said luminance signal and said chrominance signal, and for decoding said time-base corrected dropout detection signal of each channel to generate a luminance dropout signal indicating a dropout section of a luminance signal and a chrominance dropout signal indicating a dropout section of a chrominance signal, luminance dropout compensation means responsive to said luminance dropout signal for compensating for the dropout section of said luminance signal restored by said decode means, and chrominance dropout compensation means responsive to said chrominance dropout signal for compensating for the dropout section of said chrominance signal restored by said decode means.
 2. The video signal recording/reproduction device according to claim 1, wherein said time-base correcting means comprisesA/D converting means for converting said reproduced TCI signal of each channel into a digital signal, means for synchronizing said dropout detection signal of each channel with said reproduced TCI signal of each channel, a first line memory (32) for time-base correcting said digital reproduced TCI signal of each channel, and a second line memory (34) for time-base correcting said dropout detection signal of each channel.
 3. The video signal recording/reproduction device according to claim 1, wherein said decode means comprisesthird and fourth line memories provided for respective channels for holding the reproduced TCI signals and the time-base corrected dropout detection signals of the respective channels, means for reading out a luminance signals as a continuous luminance signal, means for reading out a dropout signal from said third and fourth line memories and for generating said luminance dropout signal corresponding to the dropout section of a luminance signal, a fifth line memory for holding the reproduced TCI signal and time-base corrected dropout detection signal of both channels, means for reading out said line sequential processed chrominance signal from said fifth line memory, and means for reading out a dropout detection signal from said fifth line memory for generating said chrominance dropout signal corresponding to the dropout section of said line sequential processed chrominance signal.
 4. The video signal recording/reproduction device according to claim 1, wherein said luminance dropout compensation means comprisesa 1H line memory for delaying said luminance signal restored by said decode means by 1 horizontal period, means responsive to said luminance dropout for inhibiting writing of said luminance signal into said 1H line memory in the dropout section of said luminance signal, means for averaging the input and output of said 1H line memory, and means responsive to said luminance dropout signal for selecting any of the output of said 1H line memory, the output of said averaging means and said luminance signal provided from said decode means, for providing a luminance signal which is dropout compensated. 